The present invention relates to a novel nonionic surfactant, an anionic surfactant anionizing it and a detergent composition. More specifically, the invention relates to non-alkylphenol type nonionic and anionic surfactants.
Heretofore, aliphatic alcohol alkylene oxide adducts, obtained by addition-polymerizing an alkylene oxide with aliphatic alcohols in the presence of a basic catalyst or an acidic catalyst, and anionized products thereof have been known as various surfactants, solvents, intermediates for chemicals. As compared with alkylphenol-based nonionic surfactants, aliphatic alcohol alkylene oxide adducts known heretofore, however, do not manifest sufficient surface activity in some case, for instance, result in insufficient emulsifiability, emulsion stability and low-foaming properties when used as emulsifiers. With respect to anionized products of aliphatic alcohol alkylene oxide adducts, there have been remained problems of foaming properties, detergency, stability with time of products and irritation to human skin.
In addition, there has been known a method using perchlorates as catalysts for addition of an alkylene oxide (U.S. Pat. No. 4,112,231). This method has not yet become industrially used; since the catalysts are of low catalytic activity, and, when used in an increased amount to shorten the reaction time, they cause problems such that the resulting product severely discolored to result in worsened product appearance and that the product contains aldehyde in high content.
The inventors have devoted deep study to resolve the above problems, and have found that nonionic surfactants comprising aliphatic alcohol alkylene oxide adducts having a specific composition and a specific molecular weight distribution exhibit excellent emulsifiability and detergency. Besides, they have found that such aliphatic alcohol alkylene oxide adducts can be directly produced by using two specific catalysts in combination to reach the present invention. Further, it has been found that products obtained by anionizing the resulting aliphatic alcohol alkylene oxide adducts have improved foaming properties, detergency, stability with time of products and irritation to human skin.
It is an object of the present invention to provide an aliphatic alcohol alkylene oxide adduct, having surface activities comparable to alkylphenol-based nonionic surfactants and moreover having no fear of environmental endocrine disrupters like alkylphenol-based nonionic surfactants.
It is another object of this invention to provide an anionic surfactant having improved foaming properties, detergency, stability with time of products and irritation to human skin by anionizing an aliphatic alcohol alkylene oxide adduct.
It is still another object of this invention to provide a detergent composition using the above anionic surfactant and having excellent detergency.
Thus, according to the present invention, provided are the following (I), (II), (III) and (IV).
(I) A nonionic surfactant comprising an aliphatic alcohol alkylene oxide adduct (A),
said (A) being directly produced by adding an alkylene oxide (b1) to an aliphatic alcohol (a1) and satisfying the following (i), (ii) and (iii):
(i) It comprises one compound represented by the following general formula (1) or a mixture of two or more thereof.
R1Oxe2x80x94[(C2H4O)m/(AO)n]xe2x80x94(C2H4O)pxe2x80x94Hxe2x80x83xe2x80x83(1)
In the formula, R1 is an aliphatic hydrocarbon group containing 8-24 carbon atoms or a cycloaliphatic hydrocarbon group containing 8-24 carbon atoms; A is an alkylene group containing at least 3 carbon atoms; m is 0 or an integer of 1 or more, the average thereof being in the range of 0-4, n is 0 or an integer of 1 or more, the average thereof being in the range of 0-3, p is 0 or an integer of 1 or more, the average thereof being in the range of 1-80, (m+n+p) is an integer, the average thereof being in the range of 3-81, and average of (m+p)/(m+n+p) is at least 0.5. In case of mxe2x89xa00 and nxe2x89xa00, [(C2H4O)m/(AO)n] represents block addition or random addition.
(ii) The ratio Mw/Mn of a weight-average molecular weight (Mw) to a number-average molecular weight (Mn) satisfies the following relation (2) or (3).
Mw/Mnxe2x89xa60.030xc3x97Ln(v)+1.010 (in case of v less than 10)xe2x80x83xe2x80x83(2)
Mw/Mnxe2x89xa6xe2x88x920.026xc3x97Ln(v)+1.139 (in case of vxe2x89xa710)xe2x80x83xe2x80x83(3)
Herein, v represents the average of (m+n+p) in the above general formula (1).
(iii) A distribution constant (c), determined by the following equation (4) derived from Weibull distribution law, is 1.0 or less. This is required only in the case of v up to 12.
c=(v+n0/n00xe2x88x921)/[Ln(n00/n0)+n0/n00xe2x88x921]xe2x80x83xe2x80x83(4)
Herein, v is the same in the above, n00, is the molar number of the aliphatic alcohol (a1) used in the reaction, and n0 is the molar number of the aliphatic alcohol (a1) unreacted.
(II) A process for producing an aliphatic alcohol alkylene oxide adduct,
which comprises addition reaction of an aliphatic alcohol alkylene oxide adduct (e), obtainable by adding 1-2.5 moles on the average of an alkylene oxide (b2) containing at least two carbon atoms to an aliphatic alcohol (a2) containing 1-24 carbon atoms in the presence of a catalyst (d) providing an adduct having a distribution constant cxe2x80x2 of 1.0 or less as determined by the following equation (4xe2x80x2) derived from Weibull distribution law,
with an alkylene oxide (b3) containing at least two carbon atoms in the presence of an alkaline catalyst (f).
cxe2x80x2=(vxe2x80x2+n0xe2x80x2/n00xe2x80x2xe2x88x921)/[Ln(n00xe2x80x2/n0xe2x80x2)+n0xe2x80x2/n00xe2x80x2xe2x88x921]xe2x80x83xe2x80x83(4xe2x80x2)
Herein, vxe2x80x2 represents the average addition molar number of alkylene oxide added per 1 mole of the aliphatic alcohol (a2), n00xe2x80x2 represents the molar number of the aliphatic alcohol (a2) used in the reaction, and n0xe2x80x2 represents the molar number of the aliphatic alcohol (a2) unreacted.
(III) An anionic surfactant obtainable by anionization of an aliphatic alcohol alkylene oxide adduct (Axe2x80x2),
said (Axe2x80x2) being directly produced by adding an alkylene oxide (b1) to an aliphatic alcohol (a1) and satisfying the following (iixe2x80x2), (iiixe2x80x2) and (iv).
(iixe2x80x2) The ratio Mw/Mn of a weight-average molecular weight (Mw) to a number-average molecular weight (Mn) satisfies the following relation (2xe2x80x2) or (3xe2x80x2).
Mw/Mnxe2x89xa60.030xc3x97Ln(vxe2x80x3)+1.010 (in case of vxe2x80x3 less than 10)xe2x80x83xe2x80x83(2xe2x80x2)
Mw/Mnxe2x89xa6xe2x88x920.026xc3x97Ln(vxe2x80x3)+1.139 (in the case of vxe2x80x3xe2x89xa710)xe2x80x83xe2x80x83(3xe2x80x2)
Herein, vxe2x80x3 represents the average of (mxe2x80x2+nxe2x80x2+pxe2x80x2) in the following general formula (1xe2x80x2).
(iiixe2x80x2) A distribution constant cxe2x80x3, determined by the following equation (4xe2x80x3), is 1.0 or less. This is required only in the case of vxe2x80x3 up to 12.
cxe2x80x3=(vxe2x80x3+n0/n00xe2x88x921)/[Ln(n00/n0)+n0/n00xe2x88x921]xe2x80x83xe2x80x83(4xe2x80x3)
Herein, vxe2x80x3 is the same in the above. n00 represents the molar number of the aliphatic alcohol (a1) used in the reaction, and n0 represents the molar number of the aliphatic alcohol (a1) unreacted.
(iv) It comprises one compound represented by the following general formula (1xe2x80x2) or a mixture of two or more thereof.
R1Oxe2x80x94[(C2H4O)mxe2x80x2/(AO)nxe2x80x2]xe2x80x94(C2H4O)pxe2x80x2xe2x80x94Hxe2x80x83xe2x80x83(1xe2x80x2)
Herein, R1 is an aliphatic hydrocarbon group containing 8-24 carbon atoms or a cycloaliphatic hydrocarbon group containing 8-24 carbon atoms; A is an alkylene group containing at least 3 carbon atoms; mxe2x80x2 is 0 or an integer of 1 or more, the average thereof being in the range of 0-5, nxe2x80x2 is 0 or an integer of 1 or more, the average thereof being in the range of 0-5, pxe2x80x2 is 0 or an integer of 1 or more, the average thereof being in the range of 0-10, (mxe2x80x2+nxe2x80x2+pxe2x80x2) is an integer, the average thereof being in the range of 1-20, and average of (mxe2x80x2+pxe2x80x2)/(mxe2x80x2+nxe2x80x2+pxe2x80x2) is at least 0.5. In case of mxe2x80x2xe2x89xa00 and nxe2x80x2xe2x89xa00[(C2H4O)mxe2x80x2/(AO)nxe2x80x2] represents block addition or random addition.
(IV) A detergent composition comprising the above anionic surfactant.
(I) Nonionic Surfactant
In the invention of the above (I), said aliphatic alcohol alkylene oxide adduct (A) is one or a mixture of two or more of an aliphatic alcohol alkylene oxide adduct directly produced by adding an alkylene oxide (b1) to an aliphatic alcohol (a1) (In this specification, xe2x80x9caliphatic alcoholxe2x80x9d is defined as including both aliphatic alcohol and cycloaliphatic alcohol.)
The term xe2x80x9cdirectly producedxe2x80x9d used herein means that said adducts are directly produced without any operation for fractionating unreacted alcohol or adducts of different addition molar numbers, such as through fractional distillation. Ones requiring fractionation are of no practical use to be used as usual nonionic surfactants, because of complicated process. But, ones obtained by stripping low-boiling matters or unreacted alcohol with easy operation not for the purpose of fractionation are not included.
The above (A) comprises one represented by the following general formula (1) or a mixture of two or more thereof.
R1Oxe2x80x94[(C2H4O)m/(AO)n]xe2x80x94(C2H4O)pxe2x80x94Hxe2x80x83xe2x80x83(1)
In the above formula (1), R1 is a residue of an aliphatic alcohol (a1), and represents an aliphatic hydrocarbon group or a cycloaliphatic hydrocarbon group, containing usually 8-24 (preferably 12-18) carbon atoms. Desirable emulsifiability, solubilizing power and detergency are not attained if carbon atoms in R1 are less then 8; while carbon atoms in R1 exceeding 24 is not preferred with respect to handling because of increased pouring point of the resulting alkylene oxide adduct. The above aliphatic hydrocarbon groups include straight-chain or branched, saturated or unsaturated aliphatic hydrocarbon groups (alkyl, alkenyl and alkadienyl groups); and the above cycloaliphatic hydrocarbon groups include cycloalkyl groups and polycyclic hydrocarbon groups.
Concrete examples of R1 include alkyl groups, such as octyl, nonyl, decyl, dodecyl, tridecyl, tetradecyl, hexa-decyl, octadecyl, nonadecyl, 2-ethylhexyl and 2-ethyloctyl groups. Illustrative of alkenyl groups are octenyl, decenyl, dodecenyl, tridecenyl, pentadecenyl, oleyl and gadoleyl groups. Alkadienyl groups are inclusive of linoleyl group. Exemplary of cycloalkyl groups are ethylcyclohexyl, propylcyclohexyl, octylcyclohexyl and nonylcyclohexyl groups. Polycyclic hydrocarbon groups include, for example, adamantyl group.
Aliphatic alcohols (a1) used in this invention, providing the residue R1, are alcohols containing usually 8-24 (preferably 12-18) carbon atoms and may be natural alcohols or synthetic alcohols (such as Ziegler alcohols and oxo alcohols).
Illustrative examples include saturated aliphatic alcohols, such as octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol, hexadecyl alcohol, octadecyl alcohol and nonadecyl alcohol; unsaturated aliphatic alcohols, such as octenyl alcohol, decenyl alcohol, dodecenyl alcohol, tridecenyl alcohol, pentadecenyl alcohol, oleyl alcohol, gadoleyl alcohol and linoleyl alcohol; cycloaliphatic alcohols, such as ethylcyclohexyl alcohol, propylcyclohexyl alcohol, octylcyclohexyl alcohol, nonylcyclohexyl alcohol and adamantyl alcohol. There may be used one or two or more of these. Among these aliphatic alcohols, preferred are primary or secondary ones and more preferred are primary ones. Besides, the alkyl group moiety may be linear or branched. Particularly preferred are dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol, hexadecyl alcohol and octadecyl alcohol.
In the above formula (1), the part of (C2H4O) is formed by addition of ethylene oxide (hereinafter referred to as EO). A represents an alkylene group containing at least 3 carbon atoms, preferably 3-8 carbon atoms, particularly preferably 3 carbon atoms. The part of (AO) is formed by addition of an alkylene oxide containing at least 3 carbon atoms. As such an alkylene oxide, there may be mentioned propylene oxide (hereinafter referred to as PO), 1,2- or 2,3-butylene oxide, tetrahydrofran, styrene oxide and the like. Preferred is PO.
In the above general formula (1), m is 0 or an integer of 1 or more, giving an average of usually 0-4, preferably 0-3, particularly 1-3. In general, n is 0 or an integer of 1 or more, giving an average of usually 0-3, and is preferably 0, 1 or 2. Usually, p is 0 or an integer of 1 or more, giving an average of 1-80, preferably 2-70, more preferably 3-40, most preferably 3-20. When it exceeds 80, sufficient emulsifying and solubilizing effects are not attained because of too high hydrophilcity and desired penetrativity is not obtained because of too large molecules. In the above general formula (1), n is preferably 0 or an integer of 1 or more, giving an average of usually 1-3.
Generally, (m+n+p) is an integer, the average thereof being in the range of 3-81, preferably 3-71, more preferably 3-41. If it exceeds 81, sufficient emulsifying and solubilizing effects are not attained because of too high hydrophilcity and desired penetrativity is not obtained because of too large molecules. The ratio (m+p)/(m+n+p) is usually at least 0.5, preferably 0.7-0.99. The ratio less than 0.5 results in poor emulsifying effects. The part of {(C2H4O)m/(AO)n} may be block addition [in the order of (C2H4O)m and then (AO)n] or random addition. Preferred is block addition.
Weight-average molecular weight (Mw) of the aliphatic alcohol alkylene oxide adduct (A) obtained in the invention (I) is preferably 261-5,000, particularly 300-1,200. When it is 261-5,000, surface activities, such as penetrating power, are particularly good and preferred. [Measurement of molecular weight is according to gel permeation chromatography (GPC), hereinafter these are defined as the same.]
It is necessary that the ratio Mw/Mn of Mw to number-average molecular weight (Mn) of (A) satisfies the following relation (2) or (3).
Mw/Mnxe2x89xa60.030xc3x97Ln(v)+1.010 (in case of v less than 10)xe2x80x83xe2x80x83(2)
Mw/Mnxe2x89xa6xe2x88x920.026xc3x97Ln (v)+1.139 (in case of vxe2x89xa710)xe2x80x83xe2x80x83(3)
In these relations, Ln(v) represents natural logarithm of v, and v represents the average number of addition moles of alkylene oxide (b1) added per 1 mole of aliphatic alcohol (a1), corresponding to average of the total of m, n and p which are numbers of addition moles of each alkylene oxide in the above general formula (1).
Sufficient surface activities are not attained, if the relation (2) or (3) is not satisfied, namely when the molecular weight distribution becomes broader.
In addition, it is preferred that the ratio Mw/Mn satisfies the following relation (2xe2x80x2) or (3xe2x80x2).
Mw/Mnxe2x89xa60.031xc3x97Ln(v)+1.000 (in case of v less than 10)xe2x80x83xe2x80x83(2xe2x80x2)
Mw/Mnxe2x89xa6xe2x88x920.026xc3x97Ln(v)+1.129 (in case of vxe2x89xa710)xe2x80x83xe2x80x83(3xe2x80x2)
Further, when it is possible to determine a distribution constant (c) by the following equation (4) derived from the following equation (5) of Weibull distribution law, it is necessary that (c) is not more than 1.0. Preferably, c is not more than 0.9, more preferably not more than 0.7. In the equation (4), the smaller is the value of distribution constant (c), that is, the smaller is the content of unreacted aliphatic alcohol, the narrower is the molecular weight distribution.
This equation is applicable to the case where the content of unreacted aliphatic alcohol (a1) is not less than the limit of detection (e.g. 0.001% by weight); and, in the case of (A), it is applicable up to such a level of 12 moles of the average number of addition moles of alkylene oxide (b1).
Sufficient surface activities are not attained, if c exceeds 1.
v=cxc3x97Ln(n00/n 0)xe2x88x92(cxe2x88x921)xc3x97(1xe2x88x92n0/n00)xe2x80x83xe2x80x83(5)
c=(v+n0/n00xe2x88x921)/[Ln(n00/n0)+n0/n00xe2x88x921]xe2x80x83xe2x80x83(4)
In these equations, Ln(n00/n0) represents natural logarithm of (n00/n0), v is defined above and n00 represents the molar number of the aliphatic alcohol (a1) used in the reaction, and n0 represents the molar number of the aliphatic alcohol (a1) unreacted.
In the case of n in the general formula (1) being 0, that is, in the case where only ethylene oxide is added to aliphatic alcohol (a1), it is preferred that the ratio Mw/Mn of weight-average molecular weight (Mw) to number-average molecular weight (Mn) satisfies the following relation (6) or (7) instead of relation (2) or (3).
Mw/Mnxe2x89xa60.020xc3x97Ln(v)+1.010 (in case of v less than 10)xe2x80x83xe2x80x83(6)
Mw/Mnxe2x89xa6xe2x88x920.026xc3x97Ln(v)+1.116 (in case of vxe2x89xa710)xe2x80x83xe2x80x83(7)
In the above, v represents the average number of addition moles of ethylene oxide (b1) added per 1 mole of aliphatic alcohol (a1), corresponding to the average of (m+p) in the above general formula (1).
Sufficient surface activities are not attained, if the relation (6) or (7) is not satisfied, namely when the molecular weight distribution becomes broader.
In addition, it is preferred that the ratio Mw/Mn satisfies the following relation (6xe2x80x2) or (7xe2x80x2).
Mw/Mnxe2x89xa60.018xc3x97Ln(v)+1.015 (in case of v less than 10)xe2x80x83xe2x80x83(6xe2x80x2)
Mw/Mnxe2x89xa6xe2x88x920.023xc3x97Ln(v)+1.113 (in case of vxe2x89xa710)xe2x80x83xe2x80x83(7xe2x80x2)
Among surfactants comprising the aliphatic alcohol alkylene oxide adduct (A) of the present invention, preferred are ones comprising (A) whose HLB is in the range of 5-13 (particularly 6-12) and having an emulsifying index s for a mineral oil of at least 8 (particularly at least 9), in view of especially good emulsifying effects to highly hydrophobic materials. Illustrative of preferable ones are those (A), in the formula (1), R1 being an aliphatic hydrocarbon group containing 10-20 carbon atoms, m being 1-3 on the average, n being 0-2 on the average, and p being 1-5 on the average. Particularly preferred are those (A), R1 being an aliphatic hydrocarbon group containing 12-18 carbon atoms, m being 1-3 on the average, n being 0-1 on the average, and p being 1-3 on the average. In the above and hereinafter, HLB means Griffin""s HLB according to the following equation (8).
Griffin""s HLB=(Molecular weight of EO moieties in the surfactant/Molecular weight of the surfactant)xc3x9720xe2x80x83xe2x80x83(8)
Herein, said emulsifying index s for a mineral oil, in case of using the surfactant of this invention as an emulsifier, is measured in accordance with the following method.
Three parts by weight of an emulsifier comprising a nonionic surfactant is blended with 97 parts by weight of a mineral oil having an aniline point of 70xc2x0 C. and a viscosity of 15-25 mPa.s at 25xc2x0 C.; and 5 parts by weight of the blend is thrown into a 100 ml measuring cylinder with a cap charged with 95 parts by weight of deionized water temperature-conditioned to 25xc2x0 C. Then the measuring cylinder is shaken 20 times up and down, and is allowed to stand at 25xc2x0 C. Upon observing emulsified state after 60 minutes, emulsifying index s is expressed according to grades evaluated on the basis below.
10: the state of being wholly emulsified homogeneously.
9: the whole being milky white, with a partly separated oil layer (less than 2 mm).
8: the whole being milky white, with a partly separated oil layer (2 mm or more, less than 5 mm).
7: the whole being milky white, with a partly separated oil layer (5 mm or more, less than 8 mm).
6: the whole being milky white, with a partly separated oil layer (8 mm or more, less than 10 mm).
5: the whole being milky white, with a partly separated oil layer (10 mm or more, less than 13 mm).
4: the oil layer being almost separated (13 mm or more), the oil layer being milky white, with a sign of transparency at the bottom of the aqueous layer.
3: the oil layer being almost separated (13 mm or more), the oil layer being milky white, with a sign of transparency at the lower half of the aqueous layer.
2: the oil layer being almost separated (13 mm or more), the oil layer being milky white, the whole aqueous layer being almost transparent.
1: being fully separated, both the oil layer and the aqueous layer being almost transparent.
Besides, among surfactants comprising (A) of this invention, preferred are ones comprising (A) whose HLB is in the range of 11-19 (particularly 12-18) and having an emulsifying index t for an oxidized polyethylene wax of at least 8 (particularly at least 9), in view of especially good emulsifying effects to highly hydrophilic materials. Illustrative of preferable ones are those (A), in the formula (1), R1 being an aliphatic hydrocarbon group containing 10-20 carbon atoms, m being 1-4 on the average, n being 0-3 on the average, and p being 5-20 on the average. Particularly preferred are those (A), R1 being an aliphatic hydrocarbon group containing 12-18 carbon atoms, m being 1-3 on the average, n being 1-2 on the average, and p being 5-15 on the average.
Herein, said emulsifying index t for an oxidized polyethylene wax, in case of using the surfactant of this invention as an emulsifier, is measured in accordance with the following method.
Together with ten stainless beads, 40 parts by weight of an oxidized polyethylene wax having a weight-average molecular weight of 9000-10000 and an acid number of 22-24, 11 parts of emulsifier, 0.5 parts of potassium hydrocarbon and 48.5 parts of deionized water are charged into a stainless pressure vessel, which is then sealed with nitrogen and is shaken thereafter for 30 minutes at 140xc2x0 C. under pressure of 2-3 kgf/cm2 to emulsify them. A state of 1% aqueous dilute liquid of the emulsified product thus obtained is expressed according to grades evaluated on the basis below. Particle size is measured, diluting the emulsified product with water to 1% by weight and using a particle size distribution measuring device of laser diffraction scattering type (For example, LA-700, produced by Horiba-Seisakusho).
10: an emulsion having an average particle size of less than 0.2 xcexcm.
9: an emulsion having an average particle size of 0.2 xcexcm or more, less than 0.3 xcexcm. 8: an emulsion having an average particle size of 0.3 xcexcm or more, less than 0.5 xcexcm.
7: an emulsion having an average particle size of 0.5 xcexcm or more, less than 0.6 xcexcm.
6: an emulsion having an average particle size of 0.6 xcexcm or more, less than 1.0 xcexcm.
5: an emulsion having an average particle size of 1.0 xcexcm or more and a UV (750 nm) transmission of 1% by weight aqueous solution of at least 30%.
4: an emulsion having an average particle size of 1.0 xcexcm or more and a UV (750 nm) transmission of 1% by weight aqueous solution of less than 30%.
3: paste of high viscosity
2: insufficient emulsification causing cohesive failure.
1: each component being separated.
Further, among surfactants comprising said alkylene oxide adduct (A) of the invention, preferred are ones comprising (A) having an HLB in the range of 7-15 (particularly 8-14), a solidifying point of (A) satisfying the following relation (9), in view of easy handling at lower temperature as compared with conventional aliphatic alcohol alkylene oxide adducts, along with good emulsifying effects. Emulsifying effects are especially good when HLB is in the range of 8-14. Illustrative of preferable ones are those (A), in the formula (1), R1 being an aliphatic hydrocarbon group containing 10-20 carbon atoms, m being 1-4 on the average, n being 1-3 on the average, and p being 1-20 on the average. Particularly preferred are those (A), R1 being an aliphatic hydrocarbon group containing 12-18 carbon atoms, m being 1-3 on the average, n being 1-3 on the average, and p being 2-16 on the average.
1.61xxe2x88x92102xe2x89xa6yxe2x89xa61.61xxe2x88x9292xe2x80x83xe2x80x83(9)
Herein, x represents % by weight of units represented by C2H4O in the general formula (1) formed by addition of EO, and y represents the solidifying point (xc2x0 C.) of the aliphatic alcohol alkylene oxide adduct (A).
It is further preferred that the solidifying point y satisfies the following relation (9xe2x80x2).
1.61xxe2x88x92100xe2x89xa6yxe2x89xa61.61xxe2x88x9295xe2x80x83xe2x80x83(9xe2x80x2)
Among surfactants comprising the aliphatic alcohol alkylene oxide adduct (A) of this invention, preferred are ones comprising (A) whose HLB is in the range of 7-15 (particularly 8-14) and having a detergency index for artificial soils supported on a slide glass [standardizing detergency of nonylphenol ethylene oxide 9.5 moles adduct as 100] of at least 100 (particularly at least 102), in view of excellent detergency for hard surfaces such as metals and tablewares and clothes. Illustrative of preferable ones are those (A), in the formula (1), R satisfies being an aliphatic hydrocarbon group containing 10-20 carbon atoms, m being 1-4 on the average, n being 1-3 on the average, and p being 3-15 on the average. Particularly preferred are those (A), R satisfies being an aliphatic hydrocarbon group containing 12-18 carbon atoms, m being 1-3 on the average, n being 1-3 on the average, and p being 5-10 on the average.
Herein, said detergency index is measured in accordance with the following method. Hereinafter, % means % by weight, unless otherwise specified.
Detergency test is carried out in accordance with Leenerts method (JIS K3370), using a detergent liquor formulated according to the above formulation. Six sheets of slide glasses are used as a pair of substrates for soils, and a chloroform solution of artificial soils having the following composition is used as soil components. The slide glass coated with the artificial soils is washed with an aqueous solution of 0.15% concentration of the detergent liquor as a wash liquid; and a detergency is determined according to the following equation, and a detergency index is represented as an index making detergency of nonylphenol ethylene oxide 9.5 moles adduct as 100.
Among surfactants comprising the aliphatic alcohol alkylene oxide adduct (A) of the invention, preferred are ones comprising (A) whose IILB is in the range of 10-14 (particularly 11-13) and having a viscosity index of 5% aqueous solution [standardizing viscosity of nonylphenol ethylene oxide 8.5 moles adduct as 100) of at least 50 (particularly at least 70), in view of high thickening function and usefulness as a thickener. Illustrative of preferable ones are those (A), in the formula (1), R1 being an aliphatic hydrocarbon group containing 10-20 carbon atoms, m being 1-4 on the average, n being 0-3 on the average, and p being 1-10 on the average. Particularly preferred are those (A), R1 being an aliphatic hydrocarbon group containing 12-18 carbon atoms, m being 1-3 on the average, n being 0-1 on the average, and p being 3-7 on the average.
Herein, said viscosity index is measured in accordance with the following method.
A 5% aqueous solution of a nonionic surfactant is prepared, and its viscosity is measured at 25xc2x0 C., with a Brookfield type viscometer, using a rotor No.3, at 40 rpm; and a viscosity index is represented as an index making viscosity of 5% aqueous solution of nonylphenol ethylene oxide 8.5 moles adduct as 100.
In applying nonionic surfactants of the present invention for their uses, there may be formulated other nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants. To be concrete, nonionic surfactants include, for example, polyoxyalkylene (C2-8) aliphatic (C8-24) alcohol (degree of polymerization=1-100) other than the present invention, higher fatty acid (C8-24) esters of polyoxyalkylene (C2-8, degree of polymerization=1-100) [e.g. polyethylene glycol monostearate (degree of polymerization=20), polyethylene glycol distearate (degree of polymerization=30), etc.], fatty acid (C8-24) esters of polyhydric (di- to deca- or more hydric) alcohol [e.g. glycerol monostearate, ethylene glycol monostearate, sorbitan monolaurate, etc.], fatty acid (C8-24) esters of polyoxyalkylene (C2-8, degree of polymerization=1-100) adduct of polyhydric (di- to deca- or more hydric) alcohol [e.g. polyoxyethylene (degree of polymerization=10) sorbitan monolaurate, polyoxyethylene (degree of polymerization=50) dioleic methyl glycoside, etc.], fatty acid alkanolamides [e.g. 1:1 Mole coconut oil fatty acid diethanolamide, 1:1 Mole lauroyl diethanolamide, etc.], polyoxyalkylene (C2-8, degree of polymerization=1-100) alkyl(C1-22)-phenyl ethers, polyoxyalkylene(C2-8, degree of polymerization=1-100)-alkyl(C8-24)amino ethers, and alkyl (C8-24) dialkyl (C1-6) amine oxides [e.g. lauryldimethylamine oxide etc.].
Examples of anionic surfactants include C8-24 hydrocarbon ether carboxylic acids or salts thereof [e.g. sodium lauryl polyoxyethylene (degree of polymerization=1-100) ether acetate, disodium lauryl polyoxyethylene (degree of polymerization=1-100) sulfosuccinate, etc.], salts of C8-24 hydrocarbon sulfates [e.g. sodium lauryl sulfate, sodium lauryl polyoxyethylene (degree of polymerization=1-100) ether sulfate, triethanolamine salt of lauryl polyoxyethylene (degree of polymerization=1-100) ether sulfate, sodium coconut oil fatty acid monoethanolamide polyoxyethylene (degree of polymerization=1-100) ether sulfate, etc.], salts of C8-24 hydrocarbon sulfonates [e.g. sodium dodecylbenzene sulfonate etc.], and salts of C8-24 hydrocarbon phosphate esters [e.g. sodium lauryl phosphate, sodium lauryl polyoxyethylene (degree of polymerization=1-100) ether phosphate etc.], salts of fatty acids [e.g. sodium laurate, triethanolamine laurate etc.], salts of acylated amino acids [e.g. sodium coconut oil fatty acid methyltaurate, sodium coconut oil fatty acid sarcosinate, triethanolamine coconut oil fatty acid sarcosinate, triethanolamine N-coconut oil-fatty acid-L-glutamate, sodium N-coconut oil fatty acid-L-glutamate, sodium lauroyl methyl-xcex2-alanine, etc.] and others [e.g. lauroylethanolamide sulfosuccinate disodium polyoxyethylene (degree of polymerization=1-100) etc.].
Examples of cationic surfactants include quaternary ammonium salts type [e.g. stearyl trimethyl ammonium chloride, behenyl trimethyl ammonium chloride, distearyl dimethyl ammonium chloride, lanolin fatty acid aminopropyl ethyl dimethyl ammonium ethylsulfate, etc.] and amine salts type [e.g. diethylaminoethylamide lactate stearate, dilaurylamine hydrochloride, oleylamine lactate, etc.]. Exemplary of amphoteric surfactants include betaine type amphoteric surfactants [e.g. coconut oil fatty acid amidopropyl dimethyl betaine, lauryl dimethyl betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine, lauryl hydroxysulfobetaine, sodium lauroylamidoethyl hydroxyethylcarboxymethylbetaine hydroxypropylphosphate, etc.], amino acid type amphoteric surfactants [e.g. sodium xcex2-laurylaminopropionate etc.].
Nonionic surfactants of this invention exhibit excellent performances, with respect to emulsifiability, emulsion stability, low foaming properties and the like, when used in uses, for example, emulsifiers (I), such as emulsifiers for metal working, emulsifiers for agrochemical emulsions, emulsifiers for cosmetics, emulsifiers for aqueous coatings and emulsifiers for emulsion polymerization. To be concrete, they can be used as emulsifiers for producing O/W or W/O emulsions of mineral oils; vegetable oils, e.g. castor oil, soybean oil and olive oil; animal oils and fats, such as tallow and egg yolk oil; monomers, such as styrene and acrylic esters, to which their uses are not limited.
Besides uses as emulsifiers (I), nonionic surfactants of the invention are also useful for various surfactant uses as dispersants (J) of agents for paper, such as pigments and metal salts of fatty acids; solubilizers (K) of perfumes and the like; detergents (L) as household detergents such as detergents for clothes and dish-washing detergents, and as industrial detergents such as detergents for machinery metals; and penetrating agents (M) or wetting agents (N).
In case using said aliphatic alcohol alkylene oxide adduct (A) of the present invention as emulsifiers (I), dispersants (J) or solubilizers (K), it is preferred that p in the formula (1) is such an integer of 2-40 on the average. If it exceeds 40, the resulting product is too hydrophylic and unpreferable as emulsifier, dispersant or solubilizer. Besides, Mw of (A), when used in the above uses, is preferably 261-2,000, more preferably 270-1,500.
(II) Process for Producing Nonionic Surfactant
It is preferred that said aliphatic alcohol alkylene oxide adduct (A) of the present invention is produced by the process (II) of this invention.
In the process (II) of the invention, an aliphatic alcohol alkylene oxide adduct (e) is one obtainable by adding 1-2.5 moles on the average of an alkylene oxide (b2) to an aliphatic alcohol (a2) in the presence of a catalyst (d) providing an adduct having a distribution constant cxe2x80x2 of 1.0 or less as determined by the following equation (4xe2x80x2) derived from Weibull distribution law. Through addition-reaction of an alkylene oxide (b3) containing at least two carbon atoms to this adduct (e) in the presence of an alkaline catalyst (f), an aliphatic alcohol alkylene oxide adduct of narrow molecular weight distribution is attained.
cxe2x80x2=(vxe2x80x2+n0xe2x80x2/n00xe2x80x2xe2x88x921)/[Ln(n00xe2x80x2n0xe2x80x2)+n0xe2x80x2/n00xe2x80x2xe2x88x921]xe2x80x83xe2x80x83(4xe2x80x2)
Herein, vxe2x80x2 represents the average addition molar number of the alkylene oxides (b2) and (b3) added per 1 mole of the aliphatic alcohol (a2), n00xe2x80x2 represents the molar number of the aliphatic alcohol (a2) used in the reaction, and n0xe2x80x2 represents the molar number of the aliphatic alcohol (a2) unreacted.
Aliphatic alcohols (a2) are alcohols containing usually 1-24 (preferably 8-24, particularly 12-18) carbon atoms and may be natural alcohols or synthetic alcohols (such as Ziegler alcohols and oxo alcohols). Among these, alcohols containing 8-24 carbon atoms include the same ones as (a1). Aliphatic alcohols containing 1-7 carbon atoms include, for example, saturated aliphatic alcohols, such as methanol, ethanol, propanol, butanol, pentyl alcohol, hexyl alcohol and heptyl alcohol; unsaturated aliphatic alcohols, such as propenyl alcohol, butenyl alcohol and pentenyl alcohol; and cycloaliphatic alcohols, such as methylcyclohexyl alcohol. There may be used one or two or more of these. Among these aliphatic alcohols, preferred are primary or secondary ones and more preferred are primary ones. Besides, the alkyl group moiety may be linear or branched. Particularly preferred are dodecyl alcohol, tridecyl alcohol, tetradecyl alcohol, hexadecyl alcohol and octadecyl alcohol.
As alkylene oxides (b2) and (b3), there may be mentioned alkylene oxides containing at least 2, preferably 2-8, particularly 2-3 carbon atoms. Illstrative examples include EO, PO, 1,2- or 2,3-butylene oxide, tetrahydrofran, styrene oxide and the like, and two or more may be used together. When two or more are used, they may be added block-wise or added random-wise. Among these, preferred are EO and PO.
As the catalyst (d), used is one providing a distribution constant cxe2x80x2 of the resulting alkylene oxide adduct of 1.0 or less. Preferred is one providing cxe2x80x2 of 0.7 or less, more preferably cxe2x80x2 of 0.45 or less.
Catalysts providing cxe2x80x2 of 1.0 or less include, for example, perhalogenoic acids or salts thereof, sulfuric acid or salts thereof, phosphoric acid or salts thereof and nitric acid or salts thereof. Metals in the case of forming salts are not particularly restricted, but preferably metals other than alkali metals and preferred are divalent or trivalent metals. Preferable of these metals are Mg, Ca, Sr, Ba, Zn, Co, Ni, Cu and Al; more preferred are Mg, Zn, Ca, Sr, Ba and Al, particularly Mg, Zn and Al. Halogens of perhalogenoic acids or salts thereof include chlorine, bromine and iodine, and preferred is chlorine. Thus, preferred as (d) are divalent or trivalent metal perchlorates, and more preferred are perchlorates of metal selected from the group consisting of Mg, Zn and Al. Besides, divalent or trivalent metal alcoholate may be used in combination. The amount of the metal alcoholate used together is 20-200 parts by weight per 100 parts by weight of (d). As alkyl groups of metal alcoholates, there may be mentioned lower alkyl groups (containing 1-4 carbon atoms) easy to be distilled off as alcohols, or alkyl groups of the same composition as the raw material aliphatic alcohols. Though one kind of these catalysts may be used alone, it is preferred to use two or more catalysts in conjunction [for example, magnesium perchlorate/magnesium sulfate heptahydrate=95/5-50/50, magnesium perchlorate/aluminum perchlorate=99/1-30/70 (all weight ratio)].
From the reaction rate and economical point of view, preferable amount of catalyst (d) is 0.001-1 part by weight per 100 parts by weight of the total of (a2) and (b2). More preferably it is 0.003-0.8 part by weight, particularly 0.005-0.5 part by weight.
Catalyst used in adding an alkylene oxide (b3) to an alkylene oxide adduct (e) obtained by adding (b2) to (a2) is an alkaline catalyst (f). Alkaline catalysts (f) include hydroxides of alkali metals and alkaline earth metals, for example, lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, magnesium hydroxide, calcium hydroxide and barium hydroxide; among which more preferred are potassium hydroxide and cesium hydroxide.
From the reaction rate and economical point of view, preferable amount of catalyst (f) is 0.0001-1 part by weight per 100 parts by weight of the total of (e) and (b3). More preferably it is 0.001-0.8 part by weight.
As to reaction conditions in the case of reacting (a2) with (b2), there may be mentioned methods comprising mixing (a2) with (d), carrying out nitrogen substitution, thereafter introducing (b2) at a temperature of 80-200xc2x0 C. under pressure of xe2x88x920.8-5 kgf/cm2 to a prescribed amount of (b2), followed by carrying out aging at a temperature of 80-200xc2x0 C. until the pressure within the reaction system reaches equilibrium.
To an alkylene oxide adduct (e) thus obtained, is added an alkaline catalyst (f), followed by reacting an alkylene oxide (b3) in the same manner as above to obtain an aimed aliphatic alcohol alkylene oxide adduct.
After termination of polymerization according to this invention, the resulting aliphatic alcohol alkylene oxide adduct may be used as such or through adjusting pH for various applications. If desired, the catalyst can be removed from the polymerized product, through adsorption treatment with an adsorbent, such as xe2x80x9cKyowaad 600xe2x80x9d (an adsorbent of aluminum silicate type, produced by Kyowa Chemical Ind.), followed by filtration operation. In this case, the time required for filtration operation can optionally reduced by using a filter aid of diatomaceous earth type (such as xe2x80x9cRadiolitexe2x80x9d, produced by Showa Chemical Ind.). Besides, the alkaline catalyst may be neutralized with a hydroxycarboxylic acid (such as lactic acid) as written in JP Patent Lay-open No. 112931/1981 and JP Patent Publication No. 53417/1990.
Since aliphatic alcohol alkylene oxide adducts obtained by the process (II) of the invention are of lower content of unreacted aliphatic alcohol, they can be used for the purpose of improving odor as intermediates for anionic surfactants of low odor, such as sulfated products and carboxymethylated products. They are of course useful in the above-mentioned uses, such as emulsifiers and dispersants.
(III) Anionic Surfactant
In another aspect of the present invention, provided is an anionic surfactant obtainable by anionization of an aliphatic alcohol alkylene oxide adduct (Axe2x80x2), said (Axe2x80x2) being directly produced by adding an alkylene oxide (b1) to an aliphatic alcohol (a1) and satisfying the following (iixe2x80x2), (iiixe2x80x2) and (iv).
(iixe2x80x2) The ratio Mw/Mn of a weight-average molecular weight (Mw) to a number-average molecular weight (Mn) satisfies the following relation (2xe2x80x2) or (3xe2x80x2).
Mw/Mnxe2x89xa60.030xc3x97Ln(vxe2x80x3)+1.010 (in case of vxe2x80x3 less than 10)xe2x80x83xe2x80x83(2xe2x80x2)
Mw/Mnxe2x89xa6xe2x88x920.026xc3x97Ln(vxe2x80x3)+1.139 (in case of vxe2x80x3xe2x89xa710)xe2x80x83xe2x80x83(3xe2x80x2)
Herein, vxe2x80x3 represents the average of (mxe2x80x2+nxe2x80x2+pxe2x80x2) in the following general formula (1xe2x80x2).
(iiixe2x80x2) A distribution constant cxe2x80x3, determined by the following equation (4xe2x80x3), is 1.0 or less.
cxe2x80x3=(vxe2x80x3+n0/n00xe2x88x921)/[Ln(n00/n0)+n0/n00xe2x88x921]xe2x80x83xe2x80x83(4xe2x80x3)
Herein, vxe2x80x3 is the same in the above. This is required only in the case of vxe2x80x3 up to 12, as described above. The n00 represents the molar number of the aliphatic alcohol (a1) used in the reaction, and n0 represents the molar number of the aliphatic alcohol (a1) unreacted.
(iv) It comprises one compound or a mixture of two or more thereof, represented by the following general formula (1xe2x80x2):
R1Oxe2x80x94[(C2H4O)mxe2x80x2/(AO)nxe2x80x2]xe2x80x94(C2H4O)pxe2x80x2xe2x80x94Hxe2x80x83xe2x80x83(1xe2x80x2)
Herein, R1 is an aliphatic hydrocarbon group containing 8-24 carbon atoms or a cycloaliphatic hydrocarbon group containing 8-24 carbon atoms; A is an alkylene group containing at least 3 carbon atoms; mxe2x80x2 is 0 or an integer of 1 or more, the average thereof being in the range of 0-5, nxe2x80x2 is 0 or an integer of 1 or more, the average thereof being in the range of 0-5, pxe2x80x2 is 0 or an integer of 1 or more, the average thereof being in the range of 0-10, (mxe2x80x2+nxe2x80x2+pxe2x80x2) is an integer, the average thereof being in the range of 1-20, and average of (mxe2x80x2+pxe2x80x2)/(mxe2x80x2+nxe2x80x2+pxe2x80x2) is at least 0.5. In case of mxe2x80x2xe2x89xa00 and nxe2x80x2xe2x89xa00, [(C2H4O)mxe2x80x2/(AO)nxe2x80x2] represents block addition or random addition.
The general formula (1) and the general formula (1xe2x80x2) are different with respect to the values of m, n and p and mxe2x80x2, nxe2x80x2 and pxe2x80x2, though R1 and A are the same. That is, mxe2x80x2 in the general formula (1xe2x80x2) is 0 or an integer of 1 or more, the average thereof being in the range of 0-5; while m in the general formula (1) is 0 or an integer of 1 or more, the average thereof being in the range of 0-4. In the general formula (1xe2x80x2), nxe2x80x2 is 0 or an integer of 1 or more, the average thereof being in the range of 0-5; whereas n in the general formula (1) is 0 or an integer of 1 or more, the average thereof being in the range of 0-3. In the general formula (1xe2x80x2), pxe2x80x2 is 0 or an integer of 1 or more, the average thereof being in the range of 1-10; while p in the general formula (1) is 0 or an integer of 1 or more, the average thereof being in the range of 1-80. In the general formula (1xe2x80x2), (mxe2x80x2+nxe2x80x2+pxe2x80x2) is an integer, the average thereof being in the range of 1-20; whereas (m+n+p) in the general formula (1) is an integer, the average thereof being in the range of 3-81. With respect to (m+p)/(m+n+p), the both are equally at least 0.5 on average.
As aliphatic alcohol alkylene oxide adducts (Axe2x80x2) satisfying (iixe2x80x2), (iiixe2x80x2) and (iv), there may be used alkylene oxide adducts after termination of the first step before using an alkaline catalyst or alkylene oxide adducts after termination of the second step, in the above-described production method of aliphatic alcohol alkylene oxide adduct comprising two steps, as far as they are ones satisfying (iixe2x80x2), (iiixe2x80x2) and (iv).
Methods for anionizing an aliphatic alcohol alkylene oxide adduct (Axe2x80x2) satisfying (iixe2x80x2), (iiixe2x80x2) and (iv) are not particularly restricted, as far as the terminal hydroxyl group is anionized, and include, for example, sulfation, phosphation, sulfosuccination and carboxyetherification.
As sulfation, there can be mentioned a method by sulfating the resulting aliphatic alcohol alkylene oxide adduct (Axe2x80x2) as such and then neutralizing with an alkali such as sodium hydroxide. Concretely, there may be mentioned, for instance, (a) method by using chlorosulfonic acid, (b) method by using sulfan, (c) method by using sulfamic acid and (d) method by using sulfuric acid. Sulfan of (b) is used diluted with dry nitrogen or the like.
Reaction temperature is usually 0-70xc2x0 C., preferably 10-50xc2x0 C. in the cases of (a) and (b). It is usually 50-150xc2x0 C., preferably 60-130xc2x0 C. in the cases of (c) and (d). Reaction time, which may vary depending on reaction temperature, is generally 0.1-10 hours, preferably 0.5-5 hours. Molar ratio of (Axe2x80x2) to the above sulfating agent is usually 1.0:1.2-1.0:0.8, preferably 1.0:1.1-1.0:0.9.
Reaction manners, in any cases of (a)-(d), include both continuous reaction and batch-wise reaction.
End point of sulfating reaction is such a point that the acid value (AV) represented by 56100/(molecular weight of sulfated product) reaches 90-110%, preferably 95-105%, of the theoretical value.
Besides, the end point, which may be confirmed through measuring the amount of combined sulfuric acid, is such a point that the amount of combined sulfuric acid represented by (80 xc3x97100)/(molecular weight of sulfated product) reaches 90-110%, preferably 95-105%, of the theoretical value.
Phosphation can be carried out by phosphating the resulting aliphatic alcohol alkylene oxide adduct (Axe2x80x2) with an phosphating agent, such as phosphoric acid, polyphosphoric acid, phosphoric anhydride, phosphorus oxychloride or the like, and then neutralizing with NaOH, KOH, an amine or the like. Phosphation is same as phosphoric esterification, and forms monoester, diester and the like, all these are included within the invention.
Reaction of (Axe2x80x2) with phosphoric anhydride is carried out at a reaction temperature of usually 30-150xc2x0 C., preferably 60-130xc2x0 C. within an atmosphere of nitrogen to obtain diphosphoric ester of (Axe2x80x2), followed by hydrolyzing with water equimolar of phosphoric anhydride to thereby obtain monophosphoric ester of (Axe2x80x2). Reaction time, which may vary depending on reaction temperature, is generally 1-10 hours, preferably 2-5 hours. Molar ratio of (Axe2x80x2) to the phosphoric anhydride is usually 2.0:1.15-2.0:0.85, preferably 2.0:1.05-2.0:0.95 in the case of monophosphoric ester and usually 1.0:0.4-1.0:0.6, preferably 1.0:0.45-1.0:0.55 in the case of diphosphoric ester.
End point of phosphating reaction is such a point that the acid value (AV) represented by 56100/(molecular weight of esterified product) reaches 90-110%, preferably 95-105%, of the theoretical value. Thereafter, the product is neutralized with an aqueous solution of an alkali such as NaOH or an amine to obtain an objective composition. Degree of neutralization may be optionally selected.
Sulfosuccination is a method by two step reaction processes, comprising the step of reacting (Axe2x80x2) with maleic anhydride (hereinafter referred to as MA) to obtain a monoester and the step of sulfonating it in the presence of water with a sulfite or an acid sulfite.
Reaction of (Axe2x80x2) with MA is carried out at a reaction temperature of usually 50-100xc2x0 C., preferably 60-90xc2x0 C. within an atmosphere of nitrogen to obtain a MA monoester of (Axe2x80x2). In case where MA is added in an excess amount, MA is removed under reduced pressure after termination of the monoesterification reaction. Molar ratio of (Axe2x80x2) to MA is usually 1.0:0.9-1.0:1.1, preferably 1.0:0.95-1.0:1.05.
End point of monoesterification is such a point that an acid number represented by 56100/(molecular weight of the esterified product) reaches 90-110% of the theoretical value, preferably 95-105%.
Subsequently, the resulting monoesterified product is sulfonated with a sulfite or an acid sulfite. Sulfites include, for example, alkali metal salts, such as sodium sulfite and potassium sulfite, alkaline earth metal salts, such as magnesium sulfite, and ammonium salts, such as ammonium sulfite. Acid sulfites include hydrogen sulfites, such as sodium hydrogen sulfite, potassium hydrogen sulfite, ammonium hydrogen sulfite and magnesium hydrogen sulfite. Sulfonation can be carried out by reacting the esterified product with a sulfite or an acid sulfite in the presence of water. Molar ratio of the monoesterified product to a sulfite or an acid sulfite is usually 1.0:0.9-1.0:1.1, preferably 1.0:0.95-1.0:1.05. Reaction temperature is usually 30-90xc2x0 C., preferably 40-80xc2x0 C. The reaction is usually carried out within an atmosphere of nitrogen. Reaction period, which may vary depending upon the reaction temperature, is generally 1-10 hours, preferably 2-5 hours.
End point of sulfonation is such a point that a combined surfuric acid amount represented by (80xc3x97100)/molecular weight of the sulfonated product reaches 90-110%, preferably 95-105% of the theoretical value. After sulfonation is terminated, pH is adjusted to neutralize with an organic acid such as citric acid or an alkanolamine such as triethanolamine. Carboxyetherification can be carried out, for instance, through condensation reaction of the resulting aliphatic alcohol alkylene oxide adduct (Axe2x80x2) with a mono-halo-substituted lower carboxylic acid salt, such as a monochloroacetate, a monobromoacetate, a monochloropropionate, a monobromopropionate or the like (preferably a monochloroacetate, particularly sodium monochloroacetate), in the presence of a caustic alkali and optionally a solvent.
Reaction of (Axe2x80x2) with sodium monochloroacetate can be carried out, for example, in a molar ratio of (Axe2x80x2) to sodium monochloroacetate of usually 1.0:0.90-1.0:1.60 preferably 0:0.95-1.0:1.50, at a reaction temperature of usually 30-100xc2x0 C. preferably 40-70xc2x0 C., within an atmosphere of nitrogen, using a solvent such as toluene and adding sodium hydroxide gradually. Then, purification processes such as water washing and separation are gone through to obtain a carboxyetherified product of the aliphatic alcohol alkylene oxide adduct. Thereafter, water is added thereto to obtain an aqueous solution of the carboxyetherified product of the aliphatic alcohol alkylene oxide adduct.
Degree of etherification in carboxyetherification can be measured with liquid chromatography under the following conditions.
End point is such a point that a degree of etherification reaches at least 90%, preferably at least 95%.
Kinds of anionization as described above may be variously selected, and there can be used different types depending upon uses of the resulting anionic surfactants. Among anionized products, preferred are the above-mentioned four types.
Concrete examples of preferable anionic surfactants include anionized products of (Axe2x80x2) of the general formula (1), wherein R1 is an aliphatic hydrocarbon group containing 8-18 carbon atoms, mxe2x80x2 is 0-2 on the average, nxe2x80x2 is 0-2 on the average, pxe2x80x2 is 1-3 on the average, and mxe2x80x2+nxe2x80x2+pxe2x80x2 is 1-6 on the average; and particularly preferred are anionized products of (Axe2x80x2), R1 being an aliphatic hydrocarbon group containing 8-14 carbon atoms and mxe2x80x2+nxe2x80x2+pxe2x80x2 being 1-5 on the average.
Anionic surfactants, obtain by anionizing (Axe2x80x2) satisfying (iixe2x80x2), (iiixe2x80x2) and (iv) according to the above methods, exhibit excellent forming properties and detergency. Besides, since aliphatic alcohol alkylene oxide adduct (Axe2x80x2) satisfying (iixe2x80x2), (iiixe2x80x2) and (iv) contains the raw material aliphatic alcohols only in a small amount, there can be attained ones of less skin irritation to human bodies owing to lower content of anionized products of aliphatic alcohols. In addition, odor is also bettered. Moreover, phosphated products, sulfo-succinated products and carboxyetherified products heretofore have had problems in long-term storage stablity at lower temperature and higher temperature (particularly misting or solidification at lower temperature), while products according to the present invention have remarkably improved stability. Besides, anionic surfactants of this invention, having surface activities, such as penetrating properties in addition to detergency and forming properties as above, are particularly useful as detergents, for example, shampoo, detergent for dishes, detergent for rigid surfaces such as metals.
In applying anionic surfactants thus obtained for detergents and other uses, there may be formulated other nonionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants. To be concrete, there can be mentioned those described above with respect to nonionic surfactants.
(IV) Detergent Compositions
In addition to using the anionic surfactant of the invention alone, it may be made into a detergent composition, preferably by blending a nonionic surfactant and/or an amphoteric surfactant. Illustrative of nonionic surfactants and amphoteric surfactants are those mentioned above regarding nonionic surfactants. Amounts of surfactant active ingredients formulated within compositions are, as solid content, 3-60% preferably 5-50% of the anionic surfactant of the invention, preferably 3-60% particularly 5-50% of a nonionic surfactant and preferably 1-50% particularly 2-30% of an amphoteric surfactant.
Besides, additives known heretofore can be formulated in the detergent compositions. There may be used together as such additives, humectants, such as glycerol and sodium pyrrolidone-carboxylate; high molecular weight compounds used as conditioners, such as cationized cellulose, cationized guar gum, polyethyleneglycol, sodium polyacrylate, hydroxyethyl cellulose and protein derivatives respectively having a weight-average molecular weight of 500-5,000,000; silicones, such as dimethylpolysiloxane, modified silicones having various organic groups introduced into a part of methyl groups of dimethylpolysiloxane and cyclic dimethylsiloxane; chelating agents, such as sodium ethylenediamine-tetraacetate and sodium 1-hydroxyethane-1,1-diphosphonate; lower alcohols, such as ethanol, propylene glycol and dipropylene glycol; perfumes, colorants, preservatives, ultraviolet absorbers and water.
Forms of detergent compositions, including usually liquids, pastes, solids, powders and the like, are not particularly restricted, but liquids and pastes are preferred in view of handiness. In case of liquid and paste shampoos, for example, are used the anionic surfactant of the invention in an amount of 5-30% by weight, the total of surfactants in the range of 5-50% by weight, preferably 10-30% by weight, high molecular weight compounds and silicones in an amount of 0-5% by weight, humectants, chelating agents and lower alcohols in an amount of 0-10% by weight and water in an amount of 35-95% by weight.